What is the ruling regarding fluid discharged without sexual arousal—most likely semen or pre-seminal fluid—and what are its implications concerning ghusl (ritual bath) and wudu (ablution)? Is it obligatory to re-perform previous prayers, and how does one purify oneself from it?

If it is highly probable that semen was discharged without desire, then ghusl is not obligatory. Istinja' and wudu' suffice, because in this case, its ruling is like that of urine, and this is the opinion of the majority of scholars. The acts of worship performed previously are valid as long as they were performed correctly and nothing occurred to invalidate them.